In this article I will explain with example and attached source code, how to use the Google Maps API V3 to plot driving directions and route on Google Maps using the DirectionsService.
HTML Markup
The HTML Markup consists of two TextBoxes first one for entering Source address while the other for entering destination address, a Button and three HTML DIVs for displaying the distance and duration details, plotting map and displaying directions.
<table border="0" cellpadding="0" cellspacing="3">
    <td colspan="2">
        <input type="text" id="txtSource" value="Bandra, Mumbai, India" style="width: 200px" />
        &nbsp; Destination:
        <input type="text" id="txtDestination" value="Andheri, Mumbai, India" style="width: 200px" />
        <br />
        <input type="button" value="Get Route" onclick="GetRoute()" />
        <hr />
    <td colspan="2">
        <div id="dvDistance">
        <div id="dvMap" style="width: 500px; height: 500px">
        <div id="dvPanel" style="width: 500px; height: 500px">
Calculate Distance, Travel Duration, draw (plot) Route and display Directions using DirectionsService
Inside the Google Maps window load event handler, for the source and the destination TextBoxes I have implemented Google Places Autocomplete TextBox. For more details please refer Implement Google Places Autocomplete TextBox.
When the Button is clicked, first the Map and the Directions service is initialized to display the map and the directions in their respective HTML DIVs.
Then using the source and destination addresses from the respective TextBoxes, the details of the directions, route, distance and duration are displayed inside the respective HTML DIVs.
<script type="text/javascript" src=""></script>
<script type="text/javascript">
var source, destination;
var directionsDisplay;
var directionsService = new google.maps.DirectionsService();
google.maps.event.addDomListener(window, 'load', function () {
    new google.maps.places.SearchBox(document.getElementById('txtSource'));
    new google.maps.places.SearchBox(document.getElementById('txtDestination'));
    directionsDisplay = new google.maps.DirectionsRenderer({ 'draggable': true });
function GetRoute() {
    var mumbai = new google.maps.LatLng(18.9750, 72.8258);
    var mapOptions = {
        zoom: 7,
        center: mumbai
    map = new google.maps.Map(document.getElementById('dvMap'), mapOptions);
    //*********DIRECTIONS AND ROUTE**********************//
    source = document.getElementById("txtSource").value;
    destination = document.getElementById("txtDestination").value;
    var request = {
        origin: source,
        destination: destination,
        travelMode: google.maps.TravelMode.DRIVING
    directionsService.route(request, function (response, status) {
        if (status == google.maps.DirectionsStatus.OK) {
    //*********DISTANCE AND DURATION**********************//
    var service = new google.maps.DistanceMatrixService();
        origins: [source],
        destinations: [destination],
        travelMode: google.maps.TravelMode.DRIVING,
        unitSystem: google.maps.UnitSystem.METRIC,
        avoidHighways: false,
        avoidTolls: false
    }, function (response, status) {
        if (status == google.maps.DistanceMatrixStatus.OK && response.rows[0].elements[0].status != "ZERO_RESULTS") {
            var distance = response.rows[0].elements[0].distance.text;
            var duration = response.rows[0].elements[0].duration.text;
            var dvDistance = document.getElementById("dvDistance");
           dvDistance.innerHTML = "";
            dvDistance.innerHTML += "Distance: " + distance + "<br />";
            dvDistance.innerHTML += "Duration:" + duration;
        } else {
            alert("Unable to find the distance via road.");
Google Maps API V3: DirectionsService (Driving Directions) example